1. Field of the Invention
The present invention relates generally to cleaning apparatus, and more specifically to apparatus for treating a soiled workpiece with cleaning solution. Further, the inventive apparatus herein is found to have particular utility in the auto body repair industry for the purpose of cleaning paint spray guns and related accoutrements.
2. Description of the Related Art
In many industries, tools, equipment and other workpieces need to be quickly and thoroughly cleaned. If cleaning is done by hand it is a messy and laborious process, and may expose those conducting the cleaning, and others, to harmful chemical solvents. Thus, cleaning tanks are used for many cleaning applications. Of the most convenient are those cleaning tanks having a pump and nozzles for directing a pressurized spray of cleaning solution at the workpiece.
Such cleaning tanks are used, for example, in the auto body repair industry, these being adapted to clean paint-laden equipment. However, the conventional constructions of such tanks leave much to be desired. One problem faced in designing cleaning tanks for that industry is that the solvents used, such as paint thinner and the like, create a flammable environment. Thus, air-driven pumps, rather than electrical pumps, are employed to drive solvent through conduits to nozzles aimed at workpieces such as spray gun parts. Such pumps are commonly of the reciprocating variety and are mounted on the outside wall of the solvent tank. These reciprocating pumps cause many problems when so used. For example, their reciprocating action causes these pumps to send considerable vibration throughout the system to which they are attached. This vibration tends, in time, to loosen the pump's mounting hardware, as well as other fittings and structures throughout the cleaning tank system, thereby causing leaks and other failures. These pumps also tend to be somewhat noisy.
Leakage of the pumps themselves is also a problem. These reciprocating pumps operate at fairly close tolerances, so the hard beads of paint that build up in a typical auto body shop cleaning tank system eventually cause the pump to leak and fail. Leaks pose many dangers to workers, these including fire hazards, harmful vapors and solvent burns. Further, leaking solvent creates a general environmental hazard and is likely to constitute a legal violation that invites citation.
Cleaning tanks in current use also commonly include structures such as drain cocks or other fittings in the walls and bottom of the tank where solvent is contained. No matter how well sealed, these structures and fittings are sites of potential leakage--especially when they are continually vibrated by the action of an adjacent reciprocating pump. Avoidance of these problems inherent in conventional designs adds considerable expense to their manufacture.
Thus, it appears that a need exists for a cleaning tank having a reliable, pneumatically-driven pump which poses no risk of solvent leakage to the environment, is quiet in its operation and is relatively inexpensive to manufacture.